In the art of optical signal handling, it is often desirable to provide a coupler which will connect a plurality of input optical fiber elements to a plurality of output optical fiber elements in such a way that all of the output fibers receive at least a portion of the optical signal which may appear on one or more of the input fibers. In the prior art, couplers for accomplishing this function were sometimes referred to as "star couplers" which either connected the input and output fibers directly with a plurality of smaller cross section fibers, such as is shown in the Leslie Gunderson U.S. Pat. No. 3,883,222 issued May 13, 1975, or which provided a mixing chamber, such as found in the d'Auria et al U.S. Pat. No. 4,193,661 issued Mar. 18, 1980, the Magura et al U.S. Pat. No. 4,245,884 issued Jan. 20, 1981 or the Tangonan U.S. Pat. No. 4,262,995 issued Apr. 21, 1981.
Star couplers are a major economic portion of a fiber optic bus. For example, in a 32 terminal bus system, the cost of electronic components is about two hundred dollars for each terminal, the cost of the fiber is about five dollars per meter while the cost of a star coupler is about four thousand dollars. With the evolution of fiber optic technology, the cost of cables, connectors and electronics is expected to decrease sharply causing considerable concern with respect to the cost of the star coupler.